1. Field of the Invention
The present invention relates to a probe for an in-circuit emulator, more particularly to a mechanism to reinforce a flexible substrate when the flexible substrate is used as the probe for the in-circuit emulator.
2. Description of Prior Art
An in-circuit emulator is an emulating device for substituting a part of the circuit to be mounted on an actual device for another circuit system. There is a case to use a flexible substrate as a probe for the in-circuit emulator to match an LSI package of a leadless chip carrier or a pingrid array.
A conventional probe for the in-circuit emulator using a flexible substrate is described with reference to FIGS. 5 and 6.
FIG. 5 is a schematic view of a conventional probe, in which designated 1 is a flexible substrate, 2 is a neck portion thereof, 3 is a connecting element, 4 is a connector, 6 is a base film of the substrate 1, and 5 is a pattern formed on the base film 6. The connecting element 3 is a part where an LSI package mounted on the actual device is detached therefrom and attached thereto and the detachment and attachment is repeatedly effected. The connector 4 is a part for connecting the flexible substrate 1 with the in-circuit emulator, the neck portion 2 is narrowed for connecting the connecting element 3 with the flexible substrate 1. The flexible substrate 1 is usually used for connecting parts mounted on the device with each other, and composed of a base 6 made of a plastic film which is liable to be broken or cracked when it is sharply bent or tensed. When the flexible substrate 1 in the cracked state is repeatedly used as the probe, the crack caused by a fatigue grows to reach the pattern to break finally the flexible substrate 1. To prevent the breakage of the pattern 5 caused by such cracking of the flexible substrate 1, the flexible substrate 1 is structured as shown in FIG. 3.
FIG. 6 is a cross sectional view of a neck portion of the conventional FIG. 5 probe, in which designated at 6 is a base film, 7, 8 are respectively plastic portions of the base film 6, and 13 is a covering film. The base film 6 and covering film 13 is well known in the prior art and may, for example, be of a material such as polyimide, polyamide, or polyester imide. The pattern 5 is disposed centrally of the flexible substrate 1 and away from both edges comprised of the plastic parts 7 and 8. According to the structure in FIG. 6, only plastic parts 7 and 8 remain in the neck portion 2 so that the plastic parts 7 and 8 are liable to be cracked. Once a crack is generated, it is liable to grow. Particularly, when the flexible substrate 1 is used as a probe, the neck portion 2 is liable to be deformed and broken.